Chemistry Lab

Kinetics of a Reaction

Theory:

for this lab we will be using concentrations and the temperature of a Reaction to see how it affects the reaction rate.Rate law for a reaction is a mathematical expression that relates the reaction rate to the concentration of reactants.The total rate law is determined by measuring rate,evaluating rate constant,k, and determining the rate order for each reactant.Reactions are determined by the slow step and not the fast step.Reactions must obtain a certain amount of energy in order to pass the energy barrier which is called the activation energy. It is the amount of energy needed to overcome the repulsive electron cloud forces.

Purpose:

The purpose of this lab is to determine the reaction rate can be measured and how reaction rates are affected by condition.

Pre-lab:

1A. 1:.040M/270sec=1.48x10^-4M/s

2. .080M/138sec=5.80x10^-4M/s

3. .040M/142sec=2.82x10^-4M/s

B. the concentration increased by a factor of 2, rate increase by a factor of 4. The order is second order.

C. Trial 1 and 3 should be used to determine the order of persulfate which is first order.

D. Rate law cannot be predicted using coefficients in the balanced equation

2.[NO]=4=2^X x=2 [O2]=2=2^Y y=1 K=[.0125]2[.0250]/.0282=7219.2 1/M2S

3.

Temp.

Rate constant

Temp.(K)

1/T(K-1)

Ln k

25

3.7x10-5

298.15

.00335

-10.2

35

1.3x10-4

308.15

.00324

-8.95

45

5.0x10-4

318.15

.00314

-7.60

55

1.4x10-3

328.15

.00304

-6.57

Preparation:

Part 1:

1.obtain a micro tip